The present invention relates generally to a method of splicing electrical cables together and especially to a method of splicing a power cable used to supply electricity to down hole submersible pumps and the like.
In the past, it has been common to produce oil through oil wells by down hole pumps that are activated by electric motors adjacent to the bottom of the well. Such motors are supplied with electric power by cables that extend downwardly in the wells from the ground surface. Difficulties have arisen in providing splice arrangements for connecting segments of the power cable used to supply the electricity to the down hole submersible pumps.
Currently, it is common to splice electrical power cables using an electrical crimp splice and insulating tapes to establish and maintain electrical connections between the conductive wires of power cable segments. The protective tapes, such as high modulus and high temperature tape, are wrapped around individual crimps in the power cable. The cable splice arrangements presently used are difficult and time consuming to install in the field and generally incapable of withstanding subterranean environment on a well bore over a desired period of time. Consequently, they may require frequent repair or replacement because the connections are subject to failure under the extreme pressure, temperature conditions, and high voltage stress encountered in well bore operations.
Prior art splicing techniques can be seen in U.S. Pat. No. 6,881,079 to McHugh et al. for a technique for providing power to a completion used in a subterranean environment by attaching an expandable connector that permits linear movement of the internal segments of the power cable. In U.S. Pat. No. 7,405,358 to Emerson, a splice for a down hole electrical submersible power cable has a protective housing and insulating sleeve crimp splice working in cooperation to create a sealed power cable connection. In U.S. Pat. No. 6,910,870 to Ebner, a high temper pot head is used to supply power to a submersible motor which does not require elastomeric sealing elements. In the Halpert et al. U.S. Pat. No. 6,545,221, a splice system for use in splicing coil tubing having an internal power cable is used for down hole equipment. The Ring U.S. Pat. No. 5,797,761 is for an electrical cable termination for use in oil field operation and has a female power connector for connecting to a power cable. In the Lawler et al. U.S. Pat. No. 5,478,970, an apparatus is provided for terminating an interconnecting rigid electrical cable. In the Stagi et al. U.S. Pat. No. 7,544,105, a cable and cable connection assembly is provided for connecting a first length of cable to an apparatus.
Other U.S. patents for use in splicing cables or connecting cables in a subterranean environment include the Moore U.S. Pat. Nos. 5,289,882 and 4,627,490 and 6,202,743. Also, U.S. Pat. No. 4,927,386 to Neuroth and U.S. Pat. No. 4,859,200 to McIntosh et al. and U.S. Pat. No. 5,670,747 to Lawer et al. and U.S. Pat. No. 6,881,079 to McHugh et al. Also in U.S. Patent Application Publications to Emerson US2008/0026623 and Maeland US2009/0197447 and Brotzell et al. US 2004/0012198.